Compressor head and governor assembly



Aug. 21, 1945. E. E. HEWITT COMPRESSOR HEAD ANDGOVERNOR ASSEMBLY Filed April so, 1945 2 Sheets-Sheet l wk mm. Q @Q m fp ATTORN EY Aug. 21, 1945. A E. E. HEWI TT 2,383,251

COMPRESSOR HEAD AND GOVERNOR ASSEMBLY Filed April 30, 194:5 2 Sheets-Sheet 2 INVENTOR r zmsE Hewitt ATTORNEY and high pressure .accordance with the demand for main ing structure ofthis type of compressor Patented Aug. 21, 1945 r COMPRESSOR HEAD AND GOVERNOR ASSEMBLY Ellis E. Hewitt, EdgewooL Pa assignor to The Westinghouse Air Brake Company, W ilmercling, Pa a corporation of Pennsylvania Application April 30, 1943, Serial No. 485,192

, 4 Claims. Thisinvention relates to st'eam driven aircom- I pressors, and particularly to a fluidpressureactuated governor for controlling operation of a,

compressor of the typeemployed in railway service. i i 5 a The well known steam driven compressor al ways carried on a locomotive in steam road service, and functioning to supplycompressed air to the main reservoirsfor use in the air brake systern, is controlled automatically by means of a fluid. pressure actuated governor, which is customarily interposed in the steam supply pipe leading to the operatingcylinders of the compressor. The governor in its standard form consists of a steam valve havingan operating piston, and a pair of independently operative pilot valve mechanism commonly called low pressure tops, which control the supply operating piston in reservoir 'Ihecasgovernor, some disof compressed air to the air under different service conditions.-

which is usually installed in a position tance from the compressor itself,includes a rela-E tively bulkysteam valve section requiring an individual mounting bracket for holdingthe governor device rigidly inplace on thelocomotive, and necessitates the employment of twosteam pipe connections,'which mustbe accurately made, Such a govand maintained to prevent leakage. ernor is generally" lubricated through the medium of copper tubing which is adaptedtoconductoil from a lubricator mechanism operated by the compressor.

compressor, carries adoublecylinder head containing a steam operatedpistonvalve anda mechanically actuated reversing valve, both of tion, Which forms an integral part of the cylin der head. i Another object of the invention is to provide a combination cylinder head and governor for a steam driven compressor, which are constructed and arrangedto provide'a steam inlet into which lubricant canbe introduced in the form of spray, thereby adequately lubricating all the associated operating elements from a single point.

A further object of the invention is to provide an improved compressor head having a steam supply controlling valve portion formed integrally therein, and a compressor governor constructed and arranged to be mounted on said.

valve portion without altering the normal clearance dimensions of the compressor apparatus as a whole.

Still another object of the invention is to provide an improved head and governor assembly for a steam driven compressor, in whichhead is formed a steam intake chamber containing a valve seat, lubricant atomizing means for introducing oil in the form of mist into the steam intake chamber, and a governor portion mount- A compressor of the class referred to, such asthe well known cross compound steam driven air improved steam driven compressor equipment ineluding a compressor having a cylinder head similar to;that described, but carrying a compressor governor mechanism of novel construc ed on the compressor'head and having a valve engageable :with the valve seat for controlling admission of both steam and lubricant to the governor and other operating elements contained in the head.

Other objects and advantages of the invention will appear in the following more detailed description thereof, taken in connection with the accompanying drawings, inwhich Fig. 1 is anelevational view of cross compound.

compressor having a combination cylinder head and governor assembly constructed in accordance with the invention;

Fig. 2 i a fragmentary plan view of the head and assembly shown in Fig. 1;

F g 3 is an enlarged detail view of the governor portion of the assembly, with certain parts thereof shown in section; i

Fig. 4 is a fragmentary sectional view taken substantially along the line 4-4 of Fig. 3, and

Fig. 5jis a schematic view representing the compressor in association with a main reservoir and the brake valve of an air brake system. i

As shown in Fig. 1 of the drawings, compound air compressor comprises integrally formed low and high pressure air compressing cylinders l0 and l I, a centerpiece or casting I 2 secured to the cylinder casting by means of bolts I3, a lagging casing enclosing integrally cast high and low pressure steam cylinders, the latter being indicated by the number I 4, which are located the cross 1 the steam inlet passageway I 8.

directly above the respective air cylinders l and II and are bolted to the centerpiece l2, and a double cylinder head l5 which is mounted on the integrally formed steam cylinders and secured in'place by bolts I6. The details of construction and the operation of a cross compound air compressor are well known and need not be described here, butit will be understood that live steam admitted by way of a steam inlet [1 is conducted through an inlet passage I8 formed in the wall of cylinder l4 and through other communications controlled by the compressor governor 20, presently to be described, to the usual reversing valve and steam distribution controlling valve assembled withiri the head I5, which cooperate to direct the steam into the cylinders for reciprocating the pistons of the compressor.

The compressor illustrated in Fig. l is equipped with automatic lubricator means comprisinga force feed lubricator mechanism 25, which is mounted on the second stage'or high pressure air cylinder II, and which is operative with the compressor to supply'lubricant' under pressure through a conduit 26 to an atomizer device 21 mounted on the cylinder head 5, as hereinafter more fully described. The lubricator mechanism 25 is not illustrated in detail in Fig. 1, but preferabl has a construction such as that of the apparatus disclosed and claimed in my copending application Serial No. 492,794, filed June 30, 1942, in the United States Patent Office. It will be noted that the portion of the double cylinder head 15 located directly above the cylinder M, which is the high pressure steam cylinder of the compresson'has formed thereon an elevated valve housing portion which is adapted to contain the reversing valve mecha nism always provided in'this class'of apparatus but not illustrated in the drawings. As is best shown in Figs. 1 and 4 of the drawings, the end of the compressor head 15 disposed outwardly of the valve housing portion 36 just mentioned,

and thus located above the steam inlet passageway I8 formed in the cylinder l4, carries an integral hollow ledge or bracket'portion designated generally by the reference character 32, which ledge portionconstitutesa portion of the improved compressor governor device 26 already mentioned and which serves to support the other portions of the device. I According to the invention, the hollow ledge portion 32 of the compressor head l5 has, formed therein a steam outlet passageway 34, which is adapted to communicate by way of other interior cavities, formed in the head and not illustrated, with the usual reversing valve assembly and piston valve assembly controlling the flow of steam to, the compressor pistons. Also ,formed within the ledge portion 32 of the compressor head I5 is steam inlet or atomizing chamber 35, which is separated from the steamoutlet passageway 34 by a partition 36 and which, communicates with A valve seat bushing 39 having anaperture 46 is mounted in screw-threaded relation with the partition 36 for defining a communication between the chamber and the passageway 34. The upper end of the aperture flares upwardly and outwardly to form a valve seat 4|.

The casing structure of the governor mechanism 2.0 includes a casing section 42, which is mounted on a. suitable annular mounting face 43 formed on the ledge portion 32 of the. com

pressor head, and a body section. 45 which is mounted on the upper portion of the casing section 42. The casing sections-may be secured in place by suitable fastenings, such as bolts, not shown. a

The casing section 42 has a lower portion 48 and an upper portion 49 which are joined by means of a plurality of spacedvertical portions 56, as best shown in Fig. 4 of the drawings. Mounted within the upper portion 49 is a cylindrical bushing 52 which rests on the upper end of a dish-shaped casing element 53 having 4 its lower portion mounted in engagement with the portion 48. The portion 48 has formed thereina central chamber 55 which is open to the atmosphere and contains a vertically arranged guide member 56 having a flange 51 clamped between the casing section 42 and the ledge portion43 of the compressor head. Slidably mounted in asuitable bore formed in the guide member 56 is the stem of a steam valve element 58,-which is disposed in the steam outlet passageway 34 and is adapted to engage the valve seat, of the bushing 39 carried in the compressor head;v The stem of the valve member 58 is connected to a rod 60 extending downwardly from an operating piston 6| that is slidably mounted in:the bushing 52. .Formed at the upper side of the operating piston fil is a chamber 63, which is contained inthebody'section 45 and is adapted to be supplied-with'cornpressed air, in a manner hereinafter'explained, when the governor apparatus is conditioned for cutting off the flow of steam to the'compres'sor. A restricted atmospheric'vent, not shown in the drawings, is preferably provided for normally equalizing the pressure of'fluid in" the chamber 63 with that of. the atmosphere;

Referring to Fig. 3, it will 'beobserved that and arranged to be carried on the compressor head within the clearance-limits established by the structure of the compressor itself. The portion 45a of thegovernor body section is adapted to support a pair of pilot valve assemblies, designated generally as alow pressure top 65 and a high pressure top. 66, which are. similar in construction and extend outwardly and horizontally...

as shown in Figs. 1, 2,.and 3, but. within the clearance dimensions of the compressor as'just explained. V 1 I The valve assemblies contained in the low and high pressure tops 65 and 66 are designed foroperation at difi'erent times to control operation of the compressor for maintaining a low fluid pressure in the receiving reservoir at one time and a high fluid pressure therein at'another time. For example, when thec'ompressor apparatus constitutes part of the equipment on a railway locomotive, as shown diagrammatically in Fig. 5, the low pressure'top 65 may'bearrangedto control operation 'of the compressor in charging the reservoir 91 when the associated brake valve 98 is in brake releasing position, and the high pressure top 66 may be arranged to become operative to control the compressor while the movement of the brake plication, of the brakes.

way service, and thus.

tially the same.

cover 14.

formed in a nozzle piece 92 body 85.

low pressure top is rendered inoperative upon valve to. effect an ap- This particular operational characteristic 'of the governor assembly is well understood by thosefamiliar with railneed not be furthert e xe plained. i

- For the purpose of the present disclosure, only the elements of the high pressuretop 66 need be described, it being understood that the construction-of the low pressure top65 is substanleading from the main reservoir. The valve element is subject to theopposing forces excited by a light spring 19, which urges the valve 1 element away from its seat, andta metering spring 80, which acts inwardly againsta follower member 8| and the;flexibleydiaphragm 11, the metering spring being contained within the The force exertedby the metering spring 80 may be varied in accordance with the adjustment of aset screw 83 mounted inthe cover 14. i 1 i l v The valve assembly within the lowipressure e top 65 similarly controls communication through which "compressed air may be admitted from a pipe86 and chamber 81 to the chamber 53, in accordance with! operating conditions as determined by operation of the air brakes, as

hereinbefore explained.

Thehigh pressure top com ditioned; to cut outtof operation the low pres sure top 65 of the 'governor device, whilecommunication 1 :is established between the main reservoir and the pipe 18 adjacent the high pressure top 66 for rendering the valve assembly therein efiectivetogovern operation of the compressor. With. the. pressure of air ber 1|, which pressure corresponds to that inthe main reservoir, atless than the value required, the metering spring 80; consequently maintains the valve element 15 in seated position. Since the piston chamber 63 is normally connected to the atmosphere through arrestricted port; not shown,;only the weight of. the piston El and associated elementsoppose movement of the valve chamber-M58 toits uppermost position, where it is accordingly held under the force exerted by the flow of steam entering thelcompr essor by way .ofi'thej inlet passage l8, atomizing chamber 35 andfpassa'geway 34m 1'- z r j The compressor apparatus is thereby operated to supply air under pressure to1the receiving reservoir Y 91, and 'at the same timeg'the automatic lubricating mechanism a is driven -with the compressor to supply lubricant unclerpressure to-the conduit-26 as explained in my copending patent application; supra.

\ The automatio -lubricator device is operative continuously during operation iof the compressor,

but'effects supply of; lubricant under pressure to i the conduit 26 at intervals, thefrequency'of which is determined by the speed at which the' compressor is operated' Upon each pulsation or increase in the. pressure of lubricant thus supplied throughthe conduit 26 leading to th atomizer 21 shown in Fig. 4, forced :past the Valve intotheatomizingichamber by way of the pas- Referring again to Fig. 4, the atomizing dea vice 21, which is adapted to supply lubricant under pressure and in the form of mist into the path of steam flowing through chamber 35, comprises an elbow-shaped body 85, onecportion of which is screwed into a suitably threaded opening in the compressor head I 5, and the lower end of which is joined to the tube 26 through the medium of a sealing nipple 81 and clamping nut 88. Formed in the body 85 is a valve chamber 90 which communicates with the tube 26 and by way of a passage 9| with the atomizing chamber 35 in the compressor head, the passage 9| having a limited flow capacity as dctermined by the size of a restricted orifice 9|a 85 within chamber 35. A valve element93 is secured to the body mounted within the valve chamber 90 and is normally urged into contact with a seat 94 under the force exerted by a spring 95, 'for controlling flow of lubricant from the pipe 26 to the valve chamber. The spring 95 is interposed between a follower member 91 engaging the valve element 93, and a shoulder formed on a plug member 98 screwed into the top of the The various operating parts of the compressor governor assembly are shown in Figs. 3 and 4 in the positions assumed in rendering the compressor operative to supply compressed air to the receiving reservoirs. In order to understand operation of the apparatus, it may be assumed that the air brake valve with which the compressor apparatus is associated has been consage 9|? and restricted orifice 9|a. The fine stream of lubricant thus introduced into the atomizing chamber is at once broken into small particles or atomized by the action of the inflowing steam, which then carries the finely divided lubricant into contact not only with elements of the governor mechanism 20 but also to the reversing valve and steam valve mechanisms located in the compressor head |.5.

After operation of the compressor apparatus has increased the pressure of air in the reservoir associated therewith to the value determined by the adjustment of the high pressure top 66, the corresponding fluid pressure in chamber 1| acts against the diaphragm 11 in opposition to the force of the spring 80 for permitting the unseating of the valve element 15 by spring 19. Compressed air is then admitted from the chamber 1| to chamber 63 and forces downwardly the piston 6| until the Valvemember 58 is brought into engagement with the seat bushing 39, thus cutting oil further supply of steam to the compressor. The supply of lubricant by way of the conduit 26 is likewise stopped at this time, since the automatic lubricating mechanism 25 is pneumatically linked with and operativeby the compressor.

It will be understood that the equipment illusdrawings is readily adaptable to somewhat diiferent operating conditions. For example, two compressor equipments may be provided on a locomotive and controlled from a sinmechanism such as the mechanism case the second compressor would preferably be provided with a steam cut-off valve controlled by compressed air which may be'supplied r from the chamber 63 of the illustrated equipment by way of a suitable conduit inserted 20. In this in the chama quantity of lubricant is. element 93and is injected in the aperturenormall closed bythe plug I00,

shown in Fig. 4 of the drawings. Under certain conditions it may also be desired to provide a suitable opening in the head l5 to enable connection of the atomizing chamber 35 in the compressor head directly to a steam supply pipe,

- rather than to the steam inlet passage {8 as'shown in the drawings.

From the foregoing description of the preferred embodiment of the invention, it will be evident that the improved compressor head and governor assembly may be employed in a new or rebuilt air compressor equipment for reducing pipe installation and maintenance costs, to reduce the 7 amount of space required for the equipment when mounted on a locomotive and to promote eflicut-of! valve means, said governor device including a substantially vertical body portion conformed to'fit about said elevated control valve portion and a pair of horizontally disposed pilot valve portions'extending from the body portion within the outside clearance of said air com'-.

- 3; In' a steam cylinder head assemblyfor a ciency in the operation of the associated elements in the compressor head.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A combination for a steam driven air compressor comprising a compressor head having an elevated controlling valve portion and a steam inlet passage, steam cut-ofi valve means interposed in said passage, and a governor device mounted on said head for operating said cut-off valve means, said governor device. having a casing structure conformed to fit about said elevated contro1 valve portion and substantially within the outside clearance dimensions of the compressor.

I 2. A combination head and governor assembly foria steam driven air compressor of the vertical cross-compound type comprising a compressor head having an elevated controlling valve portion and a steam inlet passage, steam cut-off valve means interposed in said passage, and a'governor device mounted on said head for operating said head and governor assembly cross-compound air compressor, the combination of a cast body portionhaving a steam inlet cham- 4. In a steam driven cross-compound air compressor for a locomotive, a combination cylinder head and compressorgovernor assemblage comprising a head section having an elevated control portion and a cored ledge portion having an ap'er tured bolting face, said ledge portion also having an interior partition carrying a valve seat and defining a steam inlet chamber and a steam. sup-'- ply passage for conducting steam intosaid control portion, a governor device mounted on said bolting face of the ledge portion, said governor'device being conformed to fit about said elevated control portion within the outside clearance dimensions of the compressor, and valve means operatively mounted in said governor device for cooperation with said valve seat within said ledge portion. v

- f ELLIS E. HEWI'I'T. 

